/* eslint-disable no-prototype-builtins,no-inner-declarations */
import { File } from 'better-xlsx'
import { saveAs } from 'file-saver'

function ExportExcel(column, dataSource, fileName = 'example') {
  // 新建工作谱
  const file = new File()
  // 新建表
  let sheet = file.addSheet('Sheet1')
  // 获取表头行数
  let depth = getDepth(column)
  // 获取表头的列数
  let columnNum = getColumns(column)
  // 新建表头行数
  let rowArr = []
  for (let k = 0; k < depth; k++) {
    rowArr.push(sheet.addRow())
  }
  // 根据列数填充单元格
  rowArr.map(ele => {
    for (let j = 0; j < columnNum; j++) {
      let cell = ele.addCell()
      cell.value = j
    }
  })
  // 初始化表头
  init(column, 0, 0)
  // 按顺序展平column
  let columnLineArr = []
  columnLine(column)
  // 根据column,将dataSource里面的数据排序，并且转化为二维数组
  let dataSourceArr = []
  dataSource.map((ele,iIdx) => {
    let dataTemp = []
    columnLineArr.map(item => {
      dataTemp.push({
        // AntDesignVue
        // [item.dataIndex]: ele[item.dataIndex],
        // value: ele[item.dataIndex],

        // Element-UI
        value: item.slotFunc != null ? item.slotFunc(ele) : ele[item.prop]
      })
    })
    dataSourceArr.push(dataTemp)
  })
  // debugger;
  // 绘画表格数据
  dataSourceArr.forEach((item, index) => {
    //根据数据,创建对应个数的行
    let row = sheet.addRow()
    row.setHeightCM(0.8)
    //创建对应个数的单元格
    item.map(ele => {
      let cell = row.addCell()
      if (ele.hasOwnProperty('num')) {
        cell.value = index + 1
      } else {
        cell.value = ele.value
      }
      cell.style.align.v = 'center'
      cell.style.align.h = 'center'
    })
  })
  //设置每列的宽度
  for (var i = 0; i < 4; i++) {
    sheet.col(i).width = 20
  }
  file.saveAs('blob').then(function(content) {
    saveAs(content, fileName + '.xlsx')
  })

  // 按顺序展平column
  function columnLine(column) {
    column.map(ele => {
      if (ele.children === undefined || ele.children.length === 0) {
        columnLineArr.push(ele)
      } else {
        columnLine(ele.children)
      }
    })
  }

  // 初始化表头
  /**
   * AntDesignVue 取值 .title
   * ElementUI 取值 .label
   * @param column
   * @param rowIndex
   * @param columnIndex
   */
  function init(column, rowIndex, columnIndex) {
    column.map((item, index) => {
      let hCell = sheet.cell(rowIndex, columnIndex)
      // 如果没有子元素, 撑满列
      if (item.label === '操作') {
        hCell.value = ''
        return
      } else if (item.children === undefined || item.children.length === 0) {
        // 第一行加一个单元格
        hCell.value = item.label
        hCell.vMerge = depth - rowIndex - 1
        hCell.style.align.h = 'center'
        hCell.style.align.v = 'center'
        columnIndex++
        // rowIndex++
      } else {
        let childrenNum = 0

        // noinspection JSAnnotator
        function getColumns(arr) {
          arr.map(ele => {
            if (ele.children) {
              getColumns(ele.children)
            } else {
              childrenNum++
            }
          })
        }

        getColumns(item.children)
        hCell.hMerge = childrenNum - 1
        hCell.value = item.label
        hCell.style.align.h = 'center'
        hCell.style.align.v = 'center'
        let rowCopy = rowIndex
        rowCopy++
        init(item.children, rowCopy, columnIndex)
        // 下次单元格起点
        columnIndex = columnIndex + childrenNum
      }
    })
  }

  // 获取表头rows
  function getDepth(arr) {
    const eleDepths = []
    arr.forEach(ele => {
      let depth = 0
      if (Array.isArray(ele.children)) {
        depth = getDepth(ele.children)
      }
      eleDepths.push(depth)
    })
    return 1 + max(eleDepths)
  }

  function max(arr) {
    return arr.reduce((accu, curr) => {
      if (curr > accu) return curr
      return accu
    })
  }

  // 计算表头列数
  function getColumns(arr) {
    let columnNum = 0
    arr.map(ele => {
      if (ele.children) {
        getColumns(ele.children)
      } else {
        columnNum++
      }
    })
    return columnNum
  }
}

export default ExportExcel
